Baseten
•
Mammoth-1
•
Released 
October 2026

Baseten
Mammoth-1

27B decision model that returns calibrated probabilities for routing, classification, and scoring instead of generating text.

Modality:
Text
model ID
baseten/mammoth-1

Output Speed *

N/A
tok/s

Intelligence Index *

N/A
/ 100

Context Window *

16384
tokens

Input price

0.6
Anytoken

Output price

0
Anytoken
Calibrated Decisions in One Forward Pass, Not Generated Text mammoth-1 is a 27B decision model from Base Labs, Baseten's research team, post-trained from Qwen3.5-27B. Instead of writing text, it reads a state and typed questions, then returns a calibrated probability for every answer option. It is the larger of the elephant-1 and mammoth-1 pair, and Baseten recommends it when a task needs broader general knowledge. It suits ticket routing, classification, guardrail checks, and rubric scoring, where your application sets the confidence thresholds. Access mammoth-1 via AnyAPI.ai

Performance

Top Jev Decision Index Score at Release, With a Thin Margin on the Artificial Analysis Replica

mammoth-1 does one job: scoring answer options in a single forward pass. Baseten reports 71.24 on the Jev Decision Index 0.4, ranking #1 of 208 models and ahead of Perplexity Decider v1.2 at 69.42. It also reports 65.9 on its own replica of the Artificial Analysis Decision Index, against 65 for d1-ultra. These are vendor-reported figures. The Jev lead is substantial, but the replica margin is narrow, so validate on your own hard cases. Per-option probabilities let you accept or escalate without parsing generated text.

Technical Specifications

What the model supports

mammoth-1 accepts text, JSON, or conversation state, optionally with images. It answers choice, yes/no, and ordinal score questions with a probability for every option. Hosted API listings show a 16,384-token context window, while BenchLM reports that the released weights config specifies 262,144 positions. Because the model writes no free text, output length is not the constraint to plan around. Input size is: the state plus all questions must fit inside the hosted window.
Verified Specifications — 
Mammoth-1
*
Input modalities
Text
output modalities
Text
Context window
16384
 tokens
Maximum output tokens
14745
Reasoning
No
Knowledge cutoff
October 2026
Pricing (standard)
0.6
 AnyTokens in
 / 
0
 AnyTokens out

Comparison

mammoth-1 or elephant-1: Which Decision Model Belongs in Your Routing Layer?

Base Labs released elephant-1 and mammoth-1 together on October 21, 2026. They share the same architecture, training data, and System One request format. The difference is scale: 27B (Qwen3.5-27B) versus 9B (Qwen3.5-9B). On Jev 0.4, mammoth-1 scores 71.24 against roughly 62.6 for elephant-1. On Base Labs' Artificial Analysis replica the two are close, at 65.9 and 65.2. The practical decision is broader knowledge and higher Jev accuracy versus faster, lower-cost decisions.

Dimension
Mammoth-1
Elephant 1
Context window *
16384
tokens
16384
tokens
Output speed *
N/A
tok/s
N/A
tok/s
Intelligence Index *
N/A
N/A
Input pricing
0.6
AnyToken
0.21
AnyToken
Output pricing
0
AnyToken
0
AnyToken
Knowledge cutoff *
October 2026
October 2026

Choose mammoth-1 when tasks depend on general knowledge, when classification is ambiguous or knowledge-heavy, or when you want the strongest Jev-measured accuracy. Choose elephant-1 when decisions are simple, latency and cost per decision dominate, and your own tests show little accuracy loss. Baseten recommends it for quick decisions. Because the replica gap is small, run both on your hardest cases before defaulting to the larger model.

Limitations & Trade-offs

Where Mammoth-1 falls short

1
No generated text. mammoth-1 returns probabilities over predefined options and never writes prose, explanations, or free-form answers. It cannot replace a chat or generation model for drafting, summarization, or reasoning traces. Workloads that need a rationale for each decision must pair it with a generative LLM. It fits only questions you can express as choice, yes/no, or ordinal score with defined criteria.
2
Vendor-reported benchmark evidence. The Jev score of 71.24 and the Artificial Analysis score of 65.9 come from Base Labs and Baseten, and the second is Base Labs' own replication. BenchLM lists no public overall rank, and no independent third-party results existed at release. For moderation or high-stakes routing, build your own hard-case set and check calibration before trusting a threshold such as 0.9.
3
Small hosted context window. Hosted listings show 16,384 tokens, although BenchLM reports a weights config of 262,144 positions. Long contracts, transcripts, or multi-document inputs must be chunked or pre-summarized, and all questions in a request share that budget. Teams classifying long documents should verify the limit on their chosen endpoint before committing.
4
Heavier than its siblings. At 27B parameters it is the largest of the family. Baseten points to elephant-1 for quick decisions, and the 2B joey-1 targets high-volume routing and guardrail checks. For simple, latency-critical triage the extra capacity may not pay off. OpenRouter also notes mammoth-1 is not available through EU in-region routing.

Best-Fit Workloads

Where this model earns its place

01

Support ticket triage and routing

‍
One request can choose the owning team, test refund intent, and rate urgency on a scale you define. Baseten's own example routes a ticket automatically when the selected option's probability is at least 0.9 and sends it to review otherwise. mammoth-1 suits queues where tickets need broader knowledge to classify. It is a poor fit if agents also need a drafted reply, since it writes no text.

02

Confidence-gated escalation

‍
mammoth-1 returns a probability for every option, so code can accept high-confidence answers and escalate uncertain ones to a human. Training included examples that teach the model when to answer "I don't know." This helps review queues and approval flows. Calibration should still be checked on your own data, because the published results are vendor-reported.

03

Guardrail and safety checks

‍
Baseten positions the mammoth-1 and elephant-1 pair for tasks ranging from ticket routing to checking requests for safety, and training data included safety and abstention examples. Yes/no probabilities let you set pass, review, or block thresholds ahead of a generative model. For very high-volume, latency-sensitive guardrails, compare it with the smaller elephant-1 or joey-1.

04

Rubric-based content scoring

‍
Ordinal score questions rate content against criteria you write, and a score can fall between rubric levels. State can include images, which suits moderation or quality review of mixed text and image content. Use it for consistent numeric grading at scale. It will not explain a score, so keep a generative judge for cases needing written justification.

Pricing in anytokens via AnyAPI
Input
0.6
₳
Output
0
₳
Cache write
—
₳
Cache read
—
₳

Integration

Access Mammoth-1 via AnyAPI.ai

Access Mammoth-1 through AnyAPI.ai using a unified API built for multi-model AI applications. Integrate Mammoth-1 without maintaining a separate provider-specific connection, and keep the flexibility to test, switch, or combine models as your application requirements evolve.

01

One API integration

Access Mammoth-1 and other AI models through the same API workflow instead of maintaining separate integrations for every provider.

02

Easy model switching

Test Mammoth-1 against alternative models or switch models as your performance, capability, or cost requirements change without rebuilding your application around another provider API.

03

Flexible for production

Use Mammoth-1 from experimentation through production while keeping your AI stack flexible as workloads, traffic, and model requirements evolve.

04

Multi-model applications

Use Mammoth-1 for the workloads where it performs best and combine it with other models for tasks that require different capabilities, performance, or efficiency.

Frequently Asked Questions

Answers to common questions about integrating and using this AI model via AnyAPI.ai

mammoth-1 is a 27B decision model from Base Labs, Baseten's research team, post-trained from Qwen3.5-27B and released October 21, 2026. It takes a state and typed questions and returns a calibrated probability for each option without generating text. Baseten's free launch period ended October 27, 2026, and usage is now paid.

Hosted API listings on OpenRouter and Vercel AI Gateway show a 16,384-token context window for mammoth-1. BenchLM reports that the released weights config specifies 262,144 positions, but Baseten publishes no context figure of its own. Verify the limit on your endpoint before sending long documents.

Baseten reports that mammoth-1 scores 71.24 on the Jev Decision Index 0.4, #1 of 208 models. It also reports 65.9 on its own replica of the Artificial Analysis Decision Index, against 65 for d1-ultra. Both are vendor-reported results, and BenchLM shows no public overall rank yet.

mammoth-1 does not generate text; it returns probabilities over predefined answer options. It accepts text, JSON, or conversation state, optionally with images, and supports choice, yes/no, and ordinal score questions. Reasoning modes and tool calling are not documented for this model.

Use mammoth-1 when tasks need broader general knowledge; use elephant-1 when quick, cheaper decisions matter more. mammoth-1 scores 71.24 on Jev 0.4 against about 62.6 for elephant-1, but the two are close on Base Labs' Artificial Analysis replica (65.9 versus 65.2). Test both on your own data.

* Benchmark data source: Artificial Analysis artificialanalysis.ai